Krystie has Tay-Sachs disease Tay-Sachs is a disease where your lysosomes aren't working right. It's a disease you get in your DNA from your parents. Both your mother and your [...]
A cell dividing into two cells The first reproduction One of the main ways we define whether something is alive is whether it can reproduce - if it can make a new [...]
Thermal proteins seen through a microscope Around four billion years ago, some of the amino acid molecules that were on the planet Earth began to join together into bigger molecules [...]
A prokaryote (seen through a microscope) What does "prokaryote" mean? The simplest living cells are called prokaryotes, which is Greek for "before the nucleus" - these are cells that were [...]
An onion skin cell (seen through a microscope) You can see the nucleus inside each cell The earliest cells, and all prokaryote cells, don't have a nucleus. Inside these simple [...]
A eukaryote cell (seen through a microscope) full of chloroplasts How do eukaryotes divide? Eukaryote cells generally reproduce themselves using a method called mitosis. When a eukaryote cell senses that there [...]
A mitochondrion (seen through a microscope) When did mitochondria evolve? About two billion years ago, in the Proterozoic, there were only prokaryotic cells on Earth. Mitochondria probably started out as [...]
When did meiosis get started? At first all eukaryote cells divided using a process called mitosis. But about 1.4 billion years ago, some eukaryote cells developed the ability to reproduce using meiosis instead. [...]
Highly magnified view of a cell wall made of lipids When did the first lipids form? Around four billion years ago, some of the amino acid molecules that were on [...]
A model of an enzyme reacting with another molecule and breaking it into two pieces. Each little ball represents an atom.This enzyme, lysozyme, breaks up bacteria in your blood to keep [...]
